Browse Topic: Braking systems

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Optimizing the Structural simulation process of Automobile Airvent knob design to evaluate the sustainability for human accidental sliding load2025-28-0289To be published on 11/06/2025
The research work elaborated the structural integrity of airvent by skipping the assembly level snap fit analysis of knob to reduce computational complexity of air vent knob sliding test post stopper. During assembly, the strain based mechanical breakage prediction of airvent sliding knob snaps is investigated in prestressed condition. The function of airvent knob is to rotate the vertical fins to divert the air flow as per comfort in intended direction identified by passenger. The airvent knob slides on central horizontal fin on a grove feature provided. Post sliding the knob to extreme end it gets stopped at end of grove feature of H fin. The sliding knob is assembled by compressing it against a silicon rubber elastomer inlay. The compression of inlay produces a constant tension on the knob snaps. The knob assembly has to sustain a passenger accidental and abrupt sliding loads while in stopped condition. The knob snaps in this press fit condition are the weak link in the accidental
Shah, Viren
Power Electronics: The Backbone of Sustainable Electrification2025-28-0228To be published on 11/06/2025
Power electronics is fundamental to sustainable electrification, enhancing energy efficiency, integrating renewable energy sources, and reducing carbon emissions. In electric vehicles (EVs), power electronics is crucial for efficient energy conversion, management, and distribution. Key components like inverters, rectifiers, and DC-DC converters optimize power from renewable sources to meet EV system requirements. In EVs, power electronics converts energy from the battery to the electric motor, ensuring efficient propulsion and regenerative braking. Inverters convert DC power from the battery to AC power for the motor, while DC-DC converters manage voltage levels for various vehicle systems. These components maximize EV energy efficiency, reduce energy losses, and extend driving range. Power electronics also supports fast and efficient battery charging, critical for widespread EV adoption. Advanced charging solutions enable rapid charging times and integration with renewable energy
Pipaliya, Akash Pravinbhai, Hatkar, Chetan
Enhancing Tipper Stability During Descent with Dynamic Angle Adjustment2025-28-0276To be published on 11/06/2025
This study addresses critical challenges faced by tippers transporting bulk cargo during descent, focusing on two major risks: cargo displacement and rear axle lifting. Prolonged descents often lead to uncontrolled shifting of cargo, such as loose aggregates or soil, within the tipper body. This phenomenon, driven by gravity, momentum, and insufficient restraint systems, poses threats of cabin damage and unpredictable ejection of materials onto the roadway. Additionally, rear axle lifting occurs due to load imbalances, increasing pressure on the front steering axle. This results in front tire slippage and inefficient steering. To tackle these issues, the study proposes a novel approach involving dynamic adjustment of the tipper lift angle to align with the road descent angle. Synchronizing the trailer bed angle with the terrain slope minimizes gravitational forces on the cargo, stabilizes its center of gravity, and ensures consistent contact between the rear tires and the road surface
Vijeth, Abhishek, Bhosle, Devidas Ashok, Cherian, Roshni, Dash, Prasanjita, Nautiyal, Anusheel
Digital Simulation of Rear Axle Brake Lines Articulation for Commercial Vehicles.2025-28-0257To be published on 11/06/2025
This paper focuses on defining the optimal length of rear axle brake lines (flexible polyamide tubes) for commercial vehicles by simulating the lines digitally by considering tube behavior and various axle articulation conditions. Currently, the length of rear axle brake lines are predominantly defined with the help of a physical mockup by articulating axle conditions in a vehicle. This approach requires actual components such as frame, axle, suspension, etc., which consumes considerable time and cost. Through technological advancements, prototyping can be reduced and convergence on digital to build can be achieved through digital simulation. This paper explores tube properties, axle configurations and definitions, and various methods of digitally simulating line articulation. Boundary conditions, space reservations and design criteria for pneumatic routing are defined for the type of line designed. Digital simulation of rear axle brake lines articulation was performed and compared
Duraiswamy, Rupesh, Sankaran, Bhargav, Raj, Santhosh
Strategies for Improving Energy Consumption for Electric Vehicles.2025-32-0092To be published on 11/03/2025
The global transition toward sustainability and decarburization has positioned Electric Vehicles (EVs) at the forefront of future mobility. While EVs inherently offer lower emissions compared to internal combustion engine (ICE) vehicles, optimizing their energy efficiency remains a critical challenge to ensure their viability, affordability, and widespread adoption. With global EV sales surpassing 10 million units in 2022 representing over 14% of the global vehicle market. Energy efficiency has emerged as a cornerstone in addressing key concerns such as range anxiety, charging infrastructure, operational costs and overall environmental impact. This paper embarks on a comprehensive journey, beginning with the historical evolution of EVs and identifying the multifaceted energy losses that occur during vehicle operation. By mapping the energy distribution within a typical EV, the study lays a foundational understanding of where and how inefficiencies arise. It then explores current
Jain, Gaurav, Premlal, P, Pathak, Rahul, Gore, Pandurang
Automatic Brake failure detection with Electromagnetic Braking system2025-28-0373To be published on 10/30/2025
Brake failure is a major cause of road accidents, contributing significantly to vehicle-related fatalities and injuries across the globe. To address this issue, this project focuses on the development of an automatic brake failure detection and integration of electromagnetic braking system to enhance vehicle safety and reliability. The system continuously monitors brake functionality by detecting anomalies in pedal free play and oil pressure levels within the braking system. If an irregularity is detected, a signal is transmitted to a microcontroller, which triggers a dashboard warning light to alert the driver, once the driver sees this light he must pull towards the service lane. If correct action is not taken within five seconds, the auxiliary electromagnetic braking system engages automatically, ensuring a controlled deceleration of the vehicle. The integration of electromagnetic brakes provides an additional layer of safety by acting as a backup braking mechanism in case of
Raja, Selvakumar
Simulation of Hydraulic Retarder using Particleworks2025-28-0382To be published on 10/30/2025
Meshless particle-based simulation methods are increasingly being considered for modeling complex physical systems, particularly those involving large fluid deformations, splashing, and sloshing effects. The effectiveness of these methods, however, depends greatly on the careful selection of simulation models and parameters. This study investigates the capabilities of Particleworks, a CFD simulation tool employing a particle-based Moving Particle Semi-implicit (MPS) solver, in simulating hydraulic retarders used in heavy-duty vehicles (HDVs). Hydraulic retarders utilize viscous drag forces generated by a spinning rotor within a fluid-filled chamber to achieve controlled braking. A dual-rotor, cup-shaped hydraulic retarder operating is analyzed in Particleworks under various conditions, including the use of different working fluids such as transmission oil, coolant, and water. The study also considered thermophysical properties with oil and examined the impact of geometrical
Kumar, Kamal S., Chaudhari, Gunjan
Evaluation of Alternative Cooling method for High Performance Resistors in zero-emission trucks.2025-28-0359To be published on 10/30/2025
High Performance Resistors (HPR), also known as brake resistors are used in zero emission vehicles (ZEVs) to dissipate excess electrical energy produced during regenerative braking, as heat energy. It is necessary to use a suitable cooling technique to release this heat energy into the atmosphere in a regulated manner. Currently in ZEVs, liquid cooled HPR with its dedicated heat exchanger and other auxiliaries such as pump, surge tank, Coolant and coolant lines, is used which increases the cost, packaging space and assembly time. This paper presents air cooling as a substitute heat-exchanging technique for high-performance resistors which eliminates the need of auxiliaries mentioned above, resulting in space optimization and reduction in assembly time. An air cooled HPR, designed for this study consists of a heat exchanger, which accommodates a resistor wire within its tubes. The design was made to fit commercial vehicle use, specific to trucks, due to packaging constraints in vehicle
MENARIYA, PRAVIN GANESH, KUMAR, VISHNU, Arhanth, Mahima, Umesha, Sathwik, Jagadish, Harshitha
Comparative Evaluation of Energy Efficiency and Performance of Electric and Counterpart Diesel Tractors2025-01-0417To be published on 10/07/2025
The objective of this trial was to compare the energy efficiency and performance of battery electric against conventional diesel tractors. Controlled road tests replicating normal operations were conducted using two electric and two diesel day-cab tractors. The test protocol was based on the TMC - Type III RP 1103A and SAE J1526 test procedures. The tests were conducted on a 110 km long route that included a 59 km hilly portion with a maximum altitude difference of 307 m. The tractors were divided into test groups of two vehicles. Trailers and drivers were switched throughout the trial between the tractors in a test group. The tests found that the two electric trucks consumed 61% and 64% less energy than their counterpart diesel trucks, respectively. Considering the production mode of electricity in Canada, the electric trucks emitted on average 82% less GHG emissions than the conventional diesel-powered tractors. The two diesel trucks showed virtually identical fuel consumption and
Surcel, Marius-Dorin, Partington, Mark, Tanguay-Laflèche, Maxime, Schumacher, Richard
Development of an SSP-180 Synchronizer Durability Test2025-01-0408To be published on 10/07/2025
Synchronizers are designed to provide smooth, efficient and safe transfer of torque between mechanical gears. Friction level, durability, and consistency of the fluid / friction lining system are crucial to ensuring crisp gear engagements without clashing and noise, vibration and/or harshness (NVH) for the life of the transmission. Excellent wear control of gears, synchronizer ring and cone surfaces is also critical to protecting the life of moving mechanical parts. The SSP-180 synchronizer rig measures friction durability and wear up to 100,000 engagements, using a variety of fluids and friction materials. Methodology for the development of a synchronizer durability procedure using the SSP-180 rig is presented for qualifying fluids for dry dual clutch (DCT) and manual transmission (MT) applications for General Motors. It will be shown that the new SSP-180 Synchronizer Durability Test in Appendix C of the dDCT fluid specification [1] satisfies four key conditions for new mechanical
Glasgow, Michael B., Zreik, Khaled, Ezanno, Philippe Nicolas, Shelton, Robert W.
Optimal Control Strategy for BEV with CVT Using Dynamic Programming Method2025-01-0407To be published on 10/07/2025
Optimal Control Strategy for BEV with CVT Using Dynamic Programming Method Authors: Hanqing Zhao, Yasuo Moriyoshi, Tatsuya Kuboyama Abstract Battery electric vehicles (BEVs) equipped with high-speed, low-torque motors can benefit greatly from the use of continuously variable transmissions (CVTs). This study aims to reduce energy consumption by adjusting the CVT ratio to ensure that the motor operates in its optimal efficiency range during both traction and regenerative braking, while delivering the required power with minimal power loss. A detailed mathematical model of a dual motor, single CVT EV powertrain and transmission structure was developed to establish an optimal control problem aimed at minimizing energy consumption. Three methods were compared to evaluate their effectiveness: (1) The basic simulation method, which directly uses the existing control map to control the CVT ratio based on torque, vehicle speed, and motor speed; (2) The steady-state method, which searches all
Zhao, Hanqing, Moriyoshi, Yasuo, Kuboyama, Tatsuya
Bolstering Driver Braking Confidence – Considerations for “Deceleration Adder” Technologies2025-01-0353To be published on 09/15/2025
Over the life of a typical vehicle (often estimated as 15 years or 300,00 km), an average driver can be expected to apply the brakes about 1.6 million times – almost 9 times per mile and over 290 times per day, and an “exuberant” driver can be expected to do this over 2.2 million times. Without question, the driver becomes accustomed to how the vehicle responds to braking control (and all of the normal variation around it), and even develops expectations for how it will respond the next time the brakes are employed. In the rare event of a failure or malfunction in the brake system resulting in an appreciably different vehicle response to the brake input, this can be surprising and even alarming to the driver, sometimes to the extent of causing hesitation in braking. Fortunately, with the rise of mechatronic braking actuators in the 1980’s and 1990’s paved the way for features such as “Driver Brake Assist” (which provides additional pressure beyond what the primary brake actuator can at
Antanaitis, David
Influence of Titanate Composition and Particle Size on Friction Stability and Wear in Brake Pads2025-01-0337To be published on 09/15/2025
The effects of particle size and composition of platelet titanates, including potassium titanate and potassium-magnesium titanate, were investigated to determine their friction stability, wear resistance, and transfer film formation. The composition and properties of titanates were characterized using X-ray diffraction (XRD), X-ray fluorescence (XRF), and particle size analysis. Tribological properties were evaluated using a tribometer (MFT-5000), while the worn surfaces were analyzed with scanning electron microscopy (SEM) and energy-dispersive spectroscopy (EDS). Results indicate that the transfer film characteristics are significantly influenced by the particle size and composition of platelet titanates. Brake pads containing potassium-magnesium titanates formed a more uniform transfer film, leading to improved friction stability and reduced wear rates. In contrast, potassium titanates increased friction levels but also resulted in higher wear on the brake friction materials. These
Jara, Diego Chavez, Lorenzana, Carlos, Sliepcevich, 1Lt Andrea, Conforti, Michael
Further Investigation of Disc Pad Compression Deformation during ISO Compressibility and Dynamic Modulus Measurements under Relatively Low Pressures2025-01-0334To be published on 09/15/2025
In an earlier publication, it was reported that the pad compressibility measured under 160 bars on NAO formulas keeps decreasing with increasing number of repeated measurements due to unrecoverable residual deformation of the friction material combined with increasing moisture adsorption, which increases the hardness of the friction material. This current investigation was undertaken to find out if this same phenomenon occurs for NAOs under a low pressure of 100 bars during compressibility measurements and under 700N during dynamic modulus measurements. In all cases, it is found that the same phenomenon occurs, meaning that friction materials become permanently compressed without full recovery, making them harder to compress and raising up the modulus. The dynamic modulus of friction material attached to a backplate is found to be lower as compared with the friction material without the backplate, which is caused by more rapid moisture adsorption of friction material pads without a
Sriwiboon, Meechai, Rhee, Seong Kwan, Sukultanasorn, Jittrathep
Actuator-to-Vehicle Joint Estimation of Clamping Force for Sensorless Control of the Electro-Mechanical Brake System2025-01-0338To be published on 09/15/2025
The electro-mechanical brake (EMB) is a promising brake actuating system for electrified vehicle. To enhance the system function safety while saving space from redundancy sensors, this paper studied sensorless climbing force control for the EMB where a new climbing force estimator is proposed by fusing the information from vehicle dynamics and EMB states. The work was done with three contributions: 1) The priori clamping force characteristics were implemented to build the estimator with two parallel models, one of which was derived from the actuator rigid-body dynamics while the other was derived from vehicle longitudinal dynamics model; 2) a proportional-integral (PI) observer utilizing wheel speed residual signals was developed to correct the initial estimates iteratively; 3) a fuzzy control controller was proposed to optimize the key parameters of the PI observer. Comparative study was conducted on a co-simulation platform and the results showed that the actuator-to-vehicle joint
Xing, Yipu, Zhou, Quan, Cheng, Yulin, Li, Congcong, Han, Wei, Zhuo, Guirong, Xiong, Lu
Preliminary Multi-Physics Modelling and Characterization of a Magneto-Rheological Brake2025-01-0347To be published on 09/15/2025
Magneto-Rheological Fluid (MRF) is a smart material used in several applications for its ability to switch from fluid behaviour to solid-like conditions if a magnetic field is present. The dependency of viscosity on magnetic field makes this fluid suitable for braking system of electric vehicles, thanks to its high controllability and response time in the whole operative range. The main parameters that influence the behaviour of the fluid, and so the braking action of the system, are magnetic field and rotational velocity. In general, the variable physical properties make it complicated to simulate the system and its behaviour in different operating conditions. Therefore, it is usually necessary to build a physical prototype to experimentally verify the response of the braking system at different driving conditions. This paper presents the development of a virtual model of Magneto-Rheological Brakes (MRB) whose validity is extended to different driving conditions. This can be
De Luca, Elena, Imberti, Giovanni, de Carvalho Pinheiro, Henrique, Carello, Massimiliana
A Study on the Prediction Method of Durability Characteristics of Brake Judder Using Simulation2025-01-0346To be published on 09/15/2025
In order to predict the durability characteristics of the brake judder, it is determined by analyzing the brake DTV (Disc Thickness Variation) and BTV(Brake Torque Variation) through the durability evaluation of the brake system or the vehicle. However, this method requires the real products and takes a long time to derive the result. When judder problems occur due to durability, there are many difficulties in deriving improvement plans through test methods. Therefore, in this study, CAE was used to derive the initial wear amount of the disc, and a method of predicting DTV after durability was developed using the results.
Hwang, Jaekeun, Kim, Sungho, Kim, Jeongkyu, Kang, Donghoon
Active Online Estimation of the Electromechanical Brake Coulomb Friction2025-01-0342To be published on 09/15/2025
Electro-mechanical braking (EMB) system has emerged as a potential candidate that serves the brake-by-wire technology. Several mechanisms are used to transmit the clamp force, where each has efficiency losses due to static friction and viscous damping. Compensating these losses is essential for accurate responses such that meeting the performance goal and improving the stopping distance of the EMB. Mathematical and empirical models are used to estimate these losses so that clamp force is accurately estimated and controlled. However, none of these models are capable of addressing the part-to-part variation or predicting the impact of other noise factors on these losses such as operating temperature and degradation. The purpose of this work is to online estimate the EMB coulomb friction by introducing an external torque command over a period of time while observing the system’s response. This approach continuously measures the coulomb friction while the system is in normal operation
Aljoaba, Sharif, Ramakrishnan, Raja, Dobbs, Jeremy
Efficient Simulation Methodology for Caliper Rattle Noise Based on a Reasonably Simplified Model and Integrated NVH CAE Approach2025-01-0348To be published on 09/15/2025
Brake caliper rattle noise is difficult to simulate due to its non-stationary, random, and broadband frequency characteristics. Many CAE engineers have adopted rattle vibration as an alternative metric to quantitative noise levels. Previous rattle noise simulations primarily presented relative displacement results derived from normal mode analysis or vibration dB levels rather than actual noise dB levels. However, rattle noise consists of continuous impact noise, which must account for reflections, diffractions, and refractions caused by transient nonlinear contacts and localized vibrations—especially during extremely short contact events. To accurately simulate impact noise, vibration and acoustic characteristics should be analyzed using a simplified structure, given the numerous mechanisms influencing impact noise generation. The rattle noise can be effectively modeled using LS-Dyna, which incorporates both explicit and BEM solvers. The correlation between test results and CAE
Park, Joosang
Enhancing Robustness of Electro-Hydraulic Brake-by-Wire Actuators via Linear Active Disturbance Rejection Control2025-01-0341To be published on 09/15/2025
In recent years, motorsport has increasingly focused on environmental concerns, leading to the rise of hybrid and fully electric competitions. In this scenario, electric motors and batteries take a crucial role in reducing the environmental impact by recovering energy during braking. However, due to inherent limitations, motors and battery cannot fully capture all braking power, necessitating the use of standard friction brakes. To achieve an efficient balance between electric motors and friction brakes, the brake pressure can no longer be directly controlled by the driver. Instead, it must be computed by the Vehicle Control Unit (VCU) and sent to a smart actuator, i.e. the Brake-By-Wire (BBW), which ensures that the required pressure is applied. The standard approach to achieve precise pressure control is to design a nested Proportional-Integral-Derivative (PID) control architecture, which requires an accurate nominal model of the system dynamics to meet the desired tracking
Gimondi, Alex, Dubbini, Alberto, Riva, Giorgio, Cantoni, Carlo
Further Investigation of Variables Affecting Brake Squeal: Porosity Effect on Lowmet Pad Properties2025-01-0335To be published on 09/15/2025
As Lowmet pad porosity increases, pad hardness decreases; pad ISO compressibility increases; the nominal friction coefficient increases (SAE J2522); and the disc wear/pad wear decreases. Brake squeal occurrence is affected by the total wear of disc and pads; the wear differential between the inboard pad and outboard pad; pad tangential taper; and pad hardness/material damping. Also, pad chamfer shape has a strong influence on brake squeal occurrence.
Rhee, Seong Kwan, Rathee, Aman, Singh, Shiv Raj, Sharma, Devendra
Effect of Casting Microstructure on the Mechanical Performance of Recycled EN AC-43200 Al-Si Alloy2025-01-0357To be published on 09/15/2025
This work investigates the influence of casting microstructure on the mechanical performance of ad hoc samples of recycled EN AC-43200 Al-Si alloy. Three batches are produced by modifying the casting process parameters (i.e., molten alloy temperature and in-mold cooling conditions) to obtain different casting microstructures. Room temperature tensile and high-cycle fatigue tests, coupled with metallography, X-ray tomography, and fatigue fracture surface analysis, are performed to elucidate the relationship between microstructural characteristics and mechanical properties of the investigated alloy. The findings indicate that casting pores and intermetallic precipitates play a pivotal role in influencing the mechanical behavior and performance of cast, recycled EN AC-43200 Al-Si alloy. Additionally, an inverse correlation between secondary dendrite arm spacing (SDAS) and both tensile properties and fatigue life is established.
Pavesi, Arianna, Barella, Silvia, D'Errico, Fabrizio, Bonfanti, Andrea, Bertasi, Federico
Applying Specialized System Analysis for Brake by Wire in Software Defined Vehicles: The Development of a System Analysis Tool (SAT)2025-01-0355To be published on 09/15/2025
The emergence of Software Defined Vehicles (SDVs) has introduced significant complexity in automotive system design, particularly for safety-critical domains such as braking. A key principle of SDV architecture is the centralization of control software, decoupled from sensing and actuation. When applied to Brake-by-Wire (BbW) systems, this leads to decentralized brake actuation that demands precise coordination across numerous distributed electronic components. The absence of mechanical backup in BbW systems further necessitates fail-operational redundancy, increasing system complexity and placing greater emphasis on rigorous system-level design validation. A comprehensive understanding of component interdependencies, failure propagation, and redundancy effectiveness is essential for optimizing such systems. This paper presents a custom-built System Analysis Tool (SAT), along with a specialized methodology tailored for modeling and analyzing BbW architectures in the context of SDVs
Heil, Edward, Zuzga, Sean, Babul, Caitlin
Brake System Homologation: A Holistic, Simulation-Based Approach2025-01-0351To be published on 09/15/2025
With the introduction of the Euro 7 regulation, non-exhaust emissions – particularly those arising from brake and tire abrasion – will be regulated and subject to emission limits for the first time. This presents significant challenges not only for OEMs striving to meet these targets within the given timeframe, but also for suppliers, who must develop innovative solutions for the precise measurement, analysis, and mitigation of these emissions. To address this, it is essential to establish and industrialize new testing methodologies as structured, scalable, and cost-efficient processes. Beyond pure measurement capability, service providers in this domain are increasingly expected to serve as feedback mechanisms – identifying process limitations, proposing targeted improvements, and thereby enabling continuous development in line with evolving technical and regulatory requirements. In this context, AVL is pursuing a holistic development strategy that integrates brake emission
Grojer, Bernd
Analysis of Front Axle Wheel End Temperature Measurements in Heavy-Duty Trucks2025-01-0364To be published on 09/15/2025
The Front Axle wheel end assembly is a critical component of Vehicle functionality, comprising a wheel hub positioned to rotate smoothly on an Axle spindle. This rotational movement is enabled by bearings positioned between the hub and the spindle, allowing for frictionless rotation. The Front Axle wheel ends’ temperature typically depends on several factors such as type of Vehicle, Load & driving conditions and health of the components involved. In general, the wheel ends can become warm during normal operation owing to friction generated by the rotation of the wheels and the interaction of various mechanical components such as Bearings and Brakes. However, if the temperature of the wheel ends becomes excessively hot, it could indicate potential issues such as Overheating brakes, Wheel bearing problems, improperly inflated tyres, and faulty components. As temperature rise, materials tend to expand. This expansion can affect the dimensions of critical components in the Front Axle wheel
Pandiyan, Mahendran, Jayaraman, Karthik, R, Sabari, B, Ellavarasan, Bhanja, Subrat Kumar
Water Interaction and Its Effect on the Tribological Behavior of NAO Friction Materials2025-01-0336To be published on 09/15/2025
Moisture is known to be a relevant factor during a friction material life, affecting tribological behaviors such as friction coefficient and torque variations. In this study we investigated the interaction between friction materials and water; employing various techniques such as contact angle measurements, water adsorption, and exposure to controlled environmental condition changes. Focusing on NAO friction material, mix modifications were studied to highlight differences and understand mechanisms, in particular, organic content and hydrophobic agents, were examined. Characterization results showed that brake pads hydrophobicity can be influenced by water interaction conditions; even low-wettability surfaces, such as those treated with hydrophobic modifiers, can still absorb water depending on internal factors (e.g., porosity) and external conditions (e.g., contact time, humidity). Additionally, we investigated the capacity of a friction material to adsorb water and desorb it back to
Iodice, Valentina, Durando, Pietro, Balestra, Simone, Pellerej, Diego
Durable Aluminum Alloys for Brake Disc and Rotor Applications2025-01-0358To be published on 09/15/2025
Lightweight materials are essential in reducing the overall weight and improving the efficiency and performance of ICE and electric vehicles. The use of aluminum alloys is critical in transitioning to a more energy sustainable and environmentally friendly future. The accessible combinations of high modulus to density and strength to weight ratios, as well as their excellent thermal conductivity, make them an ideal solution for overall weight reduction in vehicles, thereby improving fuel efficiency and reducing emissions. Aluminum alloys with high strength and lifetime thermal stability have been industrialized for usage in brake rotor applications. Amongst the most used aluminum alloys with high thermal stability are 2618-T8 and 4032-T6 for use in aerospace and automotive industries, respectively. However, when it comes to prolonging the life of a product at temperatures that exceed 200°C, the properties of these alloys will quickly degrade within the first 300 hours of exposure
Duchaussoy, Amandine, Lorenzino, Pablo, Franklin, Jack, Tzedaki, Maria
Achieving Euro 7 Compliance: Cost-Effective Brake Wear Particle Emissions and Performance with FNC-Smart ONC® GCI Rotors2025-01-0332To be published on 09/15/2025
Advanced ferritic nitrocarburizing process combined with a specialized post-oxidation treatment described as FNC + Smart ONC® [1] is developed for brake rotor applications. The process can be applied to standard grey cast iron brake rotors, significantly reducing PM 10 emissions to levels below the Euro 7 limits for most vehicles equipped with at least some recuperative braking capabilities, all without compromising performance. Finished grey iron brake rotors, ferritic nitrocarburized and post oxidized were evaluated according to several industry standards. The standards include SAE J2707B (Block Wear Test including Highway) [2], GRPE-90-24 Rev.1 Emission Test (Full WLTP Brake Cycle 6 Times) [3], and SAE J2522 (AK-Master Performance) [4]. Nitrocarburized post oxidized brake rotors were compared to untreated grey iron rotors exposed to several friction materials. Ferritic nitrocarburizing and post oxidation addresses the issue of corrosion, which is particularly relevant for brake
Winter, Karl-Michael, Holly, Mike
Development of a Laboratory Brake for a Flywheel Mass Test Rig for Variable Pad Sizes and Shapes with a Force Distribution Unit for Ideal Contact Pressure and a Topography Measurement System for In-Situ Recording of Surface Changes and Wear2025-01-0331To be published on 09/15/2025
Pin-on-disk tribometers are used to determine the frictional behaviour and boundary layer dynamics of material pairings. Material pairings are examined under defined conditions in order to reason about the friction behaviour and wear. Pairings for real brake systems with larger pad sizes can be tested on flywheel mass test rigs in order to provide proof of suitability. This is mainly due to a lack of knowledge about the scaling behaviour of friction linings. The Department of Machinery System Design at TU Berlin has combined the classic approach of a pin-on-disk tribometer with a flywheel mass test rig (up to 12.78 kgm2) and thus set up a laboratory brake on which material pairings with different pad shapes and sizes (up to 48 cm2) can be examined. The flywheel mass test rig consists of an adjustable DC-motor that drives a shaft on which variable flywheel masses and brake disks can be installed. The variability allows for different kinetic energies at different friction speeds. The
Heuser, Robert Michael, Rosenthal, Tobias Richard, Wiest, Daniel Christian, Meyer, Henning Jürgen
A Novel Framework for Elastic Constants and Damping Ratio Optimization of Friction Material in Brake Squeal Simulations2025-01-0350To be published on 09/15/2025
Friction material properties critically impact brake squeal simulation outcomes due to their nonlinear and transversely isotropic behaviors, which vary with load type and direction. To improve the reliability of brake squeal predictions, this study introduces the Transversely-isotropic Elastic Constants Optimization (TECO) method, a novel multi-dimensional constrained optimization framework for refining the elastic constants and damping ratio of friction materials. By integrating experimental testing, finite element analysis (FEA), and an advanced optimization technique - Gradient Response Surface Algorithm (GRA), the TECO method minimizes discrepancies between simulated and experimental data, ensuring accurate characterization of elastic properties. The TECO method offers significant advantages, including flexibility and robustness, making it an effective alternative to ultrasonic measurements and traditional optimization techniques, especially for anisotropic friction lining
Philip, Rony, Muralidharan, Sudharsan, Mohanam, Gopalakrishnan
A Study on the Development of Optimal Brakes for Electric Vehicles Using Simulation2025-01-0345To be published on 09/15/2025
As the ICE vehicle changes into the EV, we can use regenerative brake. It can improve not only the energy consumption but also reduce the hydraulic brake usage. The less hydraulic brake usage mitigates the heat loading on the brake disc. From this reason, the lightweight brake can be used in the EV. However, when the lightweight brake is applied, the brake NVH can be increased. The optimization design of the lightweight brake should be done to prevent the brake NVH. In this paper, the optimal brake disc thickness and brake interfaces are determined by using of disc heat capacity analysis. The lightweight brake should be optimized by using of the brake squeal analysis. We can verify the results from both analysis and test. Finally, we can have the lightweight brake, which is competitive in terms of cost, weight and robust to the brake NVH.
Kim, Sungho, Kim, Jeongkyu, Hwang, Jaekeun, Kang, Donghoon
Brake Drag Optimization: A Perspective on Virtual and Physical Tools for Developing Near-Zero Drag Sliding Calipers2025-01-0360To be published on 09/15/2025
The ever-increasing prevalence of electric vehicles in the global market continues to push automakers towards more stringent brake drag requirements. As OEMs seek to differentiate themselves with greater vehicle range to offset consumer anxiety as a barrier for entry to EVs, brake caliper suppliers see requirements for zero or near-zero drag at the component level becoming commonplace. Despite this pressure, many practical concerns exist with torque measurement capabilities in the sub 1.0 N-m range. Additionally, the authors have observed an industry tendency to employ suboptimal engineering methodology for assessing drag concerns, with trial and error attempts continuing to perplex engineers more than it provides solutions. This paper will seek to reintroduce to the reader the basic physics of brake drag from a fundamental free body diagram level, review statistical approaches for characterizing the individual forces acting within the caliper, and propose a simple – yet effective
Robere, Matthew, Retting, Joshua
An Optimized Particle Collection System for PM10 and PM2.5 Tyre Wear Emission Factors under Real-World Conditions2025-24-009309/07/2025
The growing demand for improved air quality and reduced impact on human health along with progress in vehicle electrification has led to an increased focus on accurate Emission Factors (EFs) for non-exhaust emission sources, like tyres. Tyre wear arises through mechanical and thermal processes owing to the interaction with the road surface, generating Tyre Road Wear Particles (TRWP) composed of rubber polymers, fillers, and road particles. This research aims to establish precise TRWP airborne EFs for real-world conditions, emphasizing in an efficient collection system to generate accurate PM10 and PM2.5 EFs from passenger car tyres. Particle generation replicates typical driving on asphalt road for a wide selection of tyres (different manufacturers, price ranges, fuel economy rating). Factors such as tyre load, speed and vehicle acceleration are also considered to cover various driving characteristics. The collection phase focuses on separating tyre wear particles from potential
Kontses, Dimitrios, Dimaratos, Athanasios, Kaimakamis, Thomas, Vizvizis, George, Ouzounis, Rafail, Koutsokeras, Odysseas, Samaras, Zissis
An Eco-Charging Strategy for Heavy-Duty Electric Vehicles via Graph Optimization2025-24-011609/07/2025
An optimization framework for trip and charging planning for electric heavy-duty vehicles is proposed in this paper. Building upon and extending previous work on light-duty vehicles, our approach models energy-aware routing by constructing a state-augmented graph that jointly captures geographic position and battery state-of-charge. We refine the route model to include detailed vehicle dynamics and speed constraints specific to heavy-duty vehicles, and introduce an alternative graph construction method that avoids the computational complexity of lexicographic products by generating only feasible nodes. The resulting framework enables efficient trip planning that accounts for driving behavior, road characteristics, and charging infrastructure. Simulation results demonstrate the effectiveness of the approach in reducing energy consumption and ensuring operational feasibility for long-haul freight transport.
Zonetti, Daniele, Sciarretta, Antonio, De Nunzio, Giovanni
S.I.S.T.E.R.: An Integrated Approach to Non-Exhaust Emissions2025-24-009109/07/2025
As electric mobility spreads and evolves, non-exhaust Particulate Matter (PM) sources are gaining more attention for total vehicular emissions. A holistic approach for studying the involved phenomena is necessary to identify the parameters that have the greatest impact on this portion of emissions. To achieve this, it is necessary to develop a new platform capable of both creating testing methodologies for future regulations and enabling the parallel development of advanced tyres and brakes that meet these standards, by correlating vehicle dynamics, driving style, tyre and brake characteristics, and the resulting emissions. Here the authors present the Sustainable Integrated System for Total non-Exhaust Reduction (S.I.S.T.E.R.) project, funded by the Italian Centro Nazionale per la Mobilità Sostenibile (MOST), that aims to develop an integrated approach to study tyre/brake-related emissions from the initial stages of compound development to outdoor vehicle tests, allowing actions to be
Genovese, Andrea, De Robbio, Roberta, Lenzi, Emanuele, Caiazza, Antonio, Lippiello, Felice, Costagliola, Maria Antonietta, Marchitto, Luca, Serra, Antonio, Arimondi, Marco, Bardini, Perla
DLR Tire and Road Wear Particle Emission Testing Methodology–Collection System Influence and Repeatability Assessments2025-24-009209/07/2025
Tire and road wear particles (TRWP) have emerged as air quality hazardous matters and significant sources of airborne microplastic pollution, contributing to environmental and human health concerns. Regulatory initiatives, such as the Euro 7 standards, emphasize the urgent need for standardized methodologies to quantify TRWP emissions accurately. Despite advancements in measuring tire abrasion rates, critical gaps persist in the characterization of airborne TRWP, particularly regarding the influence of collection system design and influencing parameters on measurement accuracy and repeatability. This study addresses these challenges by designing a controlled methodological framework that aims to minimize the influencing effects and ensure comparability in TRWP emission quantification results. At the German Aerospace Center (DLR) dynamometer testbench in Stuttgart, Germany, a methodical framework was established to ensure the repeatability and comparability of TRWP measurements
Celenlioglu, Melis Seren, Epple, Fabius, Reijrink, Nina, Löber, Manuel, Reiland, Sven, Vecchi, Roberta, Philipps, Franz
Dimensional Compatibility for Commercial Vehicles Fitment of Complete Wheels in Drum Brake Applications - Truck and BusJ1865_202508 (Current)08/22/2025
This SAE Recommended Practice defines a clearance line for establishing dimensional compatibility between drum brakes and wheels with 19.5-inch, 22.5-inch, and 24.5-inch diameter rims. Wheels designed for use with drum brakes may not be suitable for disc brake applications. The lines provided establish the maximum envelope for brakes, including all clearances, and minimum envelope for complete wheels to allow for interchangeability. This document addresses the dimensional characteristics only and makes no reference to the performance, operational dynamic deflections, or heat dissipation of the system. Valve clearances have not been included in the fitment lines. Bent valves may be required to clear brake drums. Disc brake applications may require additional running clearances beyond those provided by the minimum contour lines. Mounting systems as noted are referenced in SAE J694.
Truck and Bus Wheel Committee
Comprehensive Analysis of Aero-Thermal Flow Characteristics in an Agricultural Tractor Using Computational Fluid Dynamics Simulation05-19-02-001408/01/2025
This study employs computational fluid dynamics (CFD) to analyze airflow and thermal characteristics within an agricultural tractor, focusing on operator comfort and component safety. Initial simulations identified hotspots, such as the brake pedals, operator platform, and hand throttle, where temperatures exceeded acceptable limits (rise over ambient, ROA). A multi-step approach—including sealing air leaks, adding heat insulation materials, and optimizing the deflector guard—was implemented to mitigate excessive heat. While these modifications significantly improved temperature conditions on the right platform, the left brake pedal remained problematic. Further enhancements, such as sealing an electrical socket and modifying the shroud design, effectively reduced heat exposure. The improved shroud also led to a slight decrease in static pressure (2.21%) and an 8.61% reduction in power consumption, improving airflow efficiency. Although an alternative ring fan design reduced power
Mohan, Anand, Soni, Peeyush, Sethuraman, Sriraman, Govindan, Senthilkumar, Sakthivel, Ananth, Babu, Rathish Maller
The Analysis and Optimization Approach for Solving the Thermomechanical Issues of Automotive Disk Brake15-18-03-001307/09/2025
The thermal characteristics of brakes significantly influence the braking performance of passenger vehicles. During braking, most of the vehicle’s kinetic energy is converted into internal energy in the brake disk through friction, leading to complex coupled thermomechanical issues. This article focuses on the analysis of a disk brake from a specific vehicle model. Using STAR-CCM+, a virtual disk brake bench simulation model was established. Based on the multi-timescale and multi-field coupled simulation method, the analysis of the brake disk temperature and field distributions under cyclic braking conditions was carried out. Subsequently, this work investigated the effects of factors such as thermal conduction, thermal radiation, and the shape of ventilation ribs on the heat generation and dissipation characteristics of the brake disk. Finally, a thermal deformation simulation and optimization method was developed using STAR-CCM+, ABAQUS, and ALTAIR OPTISTRUCT software. In comparison
Jiang, Daxin, Han, Chao, Deng, Jianjiao, Jia, Qing, Zhao, Wentao
Simulation-Based Investigation and its Experimental Validation of the Thermal Behaviour of a Battery Electric City Bus2025-01-026607/02/2025
Electrification of city busses is an important factor for decarbonisation of the public transport sector. Due to its strictly scheduled routes and regular idle times, the public transport sector is an ideal use case for battery electric vehicles (BEV). In this context, the thermal management has a high potential to decrease the energy demand or to increase the vehicles range. The thermal management of an electric city bus controls the thermal behaviour of the components of the powertrain, such as motor and inverters, as well as the conditioning of the battery system and the heating, ventilation, and air conditioning (HVAC) of the drivers’ front box and the passenger room. The focus of the research is the modelling of the thermal behaviour of the important components of an electric city bus in MATLAB/Simscape including real-world driving cycles and the thermal management. The heating of the components, geometry and behaviour of the cooling circuits as well as the different mechanisms of
Schäfer, Henrik, Meywerk, Martin, Hellberg, Tobias
Power Hop Detection in High-Torque Vehicles: A Machine Learning Approach with Focus on Data Coverage and Model Generalization2025-01-027107/02/2025
Power hop is a vibration phenomenon that occurs during high accelerations from low speed. In severe cases it can lead to component damage or deformation. Therefore, the affected vehicles must be safeguarded against these vibrations by a safe design of the components and by additional software-based functions. Conventional software-based solutions, such as Traction Control Systems (TCS), often perform delayed interventions and apply harsh torque adjustments that reduce driving comfort. Motivated by these challenges, this paper proposes a novel approach for power hop detection in a high-torque vehicle based on Long Short-Term-Memory Network (LSTM) and real-time measurements. Unlike conventional methods, our LSTM precisely detects the start of power hop, enabling proactive torque adjustments. Due to its impact on vehicle stability, the model must achieve a high level of reliability and robustness. Given the importance of data quality in Machine Learning (ML), we consider data-related
Chehoudi, Moatez, Moisidis, Ioannis, Sailer, Marc, Peters, Steven
Kinetic Energy Recovery: Assessment on the impact of Permanent Magnet Synchronous Motor and Battery Dynamic models2025-01-030307/02/2025
This paper examines the influence of a detailed dynamic model of a Surface Permanent Magnet Synchronous Motor (SPMSM) on the accurate evaluation of kinetic energy recovery during braking in a mild hybrid vehicle. The model, implemented in MATLAB Simulink, is based on the motor’s DQ equivalent circuit, accounting for transient effects, inductance variability, and magnetic saturation. Also, a 2nd Order Thevenin Equivalent model of the battery is used in order to take into account the bus voltage variability. Simulations reveal that the dynamic model predicts significant variations in energy recovery potential, with differences of up to 25% compared to static models under specific braking conditions. These discrepancies are particularly pronounced during high-speed high-torque transitions, where transient electrical behaviors strongly influence energy recovery. The model’s accuracy enhances the reliability of energy simulations, especially in scenarios involving frequent or intense
Lombardi, Simone, Federici, Leonardo, Tribioli, Laura, Bella, Gino
Leveraging LLM-Based AI Agents for Boosting Vehicle Testing Process2025-01-030007/02/2025
The validation process in research and development involves several complex stages, including test requests, planning, execution, and the analysis and evaluation of results. In the automotive domain, compliance with regulatory standards, such as those required for Euro 7 homologation, adds an additional layer of complexity. Implementing these regulations into operational validation workflows and ensuring their seamless integration with supporting tools remains a significant challenge. Recent advancements in Large Language Models (LLMs) have introduced innovative use cases across various domains. In particular, AI agents powered by LLMs demonstrate immense potential by autonomously performing complex tasks while utilizing user-defined tools. This capability extends far beyond traditional applications like knowledge management or text generation typically associated with LLMs. In this paper, we explore how a modern AI agent can be developed and integrated into existing IT tools for test
Unterschütz, Stefan, Hansen, Björn
Methodology for Fast-Running, Time-Resolved Simulation of Non-Exhaust Particle Emissions from Brake Wear Abrasion2025-01-027507/02/2025
Non-exhaust particle emissions, particularly those generated by brake wear, are a significant source of fine particulate matter in urban environments. These emissions contribute to air pollution and pose serious health risks, particularly in densely populated areas. While vehicle exhaust emissions have been extensively studied and regulated, the contribution of non-exhaust sources, including brake wear, remains a critical factor in air quality management. This paper presents a novel methodology for fast-running, time-resolved simulation of non-exhaust particle emissions, specifically those from brake wear abrasion. A 3D CFD model computes the turbulent flow field around the disc brake. The resulting information on the convective air cooling is applied as boundary conditions on a 3D thermal model. This thermal simulation setup is compared and verified with experimental data from literature. The 3D numerical models produce data and boundary conditions for an efficient 1D numerical
Herkenrath, Ferris, Lückerath, Moritz, Günther, Marco, Pischinger, Stefan
Longitudinal Dynamic Metrics for Describing and Developing the Deceleration Behavior of Vehicles in the Concept Phase2025-01-026407/02/2025
The brake system is a critical safety component in motor vehicles. Advances in the electrification of the powertrain and the rise of autonomous driving technologies are significantly impacting the brake system, which allows innovative approaches and necessitating the development of new brake concepts and new deceleration strategies. A major technological advance is the decoupling of the driver from the brake system through Brake-by-wire technology. A crucial attribute of Brake-by-wire systems is the attainment of a concept-independent deceleration behavior. To establish a consistent and brand-specific deceleration behavior in the early development phase, objective metrics and perceptual thresholds are required to describe the desired subjective braking behavior. Moreover, objective metrics are indispensable for the virtual phase of the vehicle development process. This article focuses on deceleration from a straight-ahead drive. To identify objective metrics and perceptual thresholds
Biller, Ralph, Udovicic, Matej, Ketzmerick, Erik, Kirch, Sebastian, Mayr, Stefan, Prokop, Günther, Wagner, Andreas
Development and Evaluation of a Combined Driveline Oscillation and Traction Controller Using Model Predictive Control and Reinforcement Learning: A Comparative Case Study2025-01-029107/02/2025
In electric vehicles, the control of driveline oscillations and tire traction is critical for guaranteeing driver comfort and safety. Yet, achieving sufficient driveline control performance remains challenging in the presence of rapidly varying road conditions. Two promising avenues for further improving driveline control are adaptive model predictive control (MPC) and model-based reinforcement learning (RL). We derive such controllers from the same non-linear vehicle model and validate them through pre-defined test scenarios. The MPC approach employs input and output trajectory tracking with soft constraints to ensure feasible control actions even in the presence of constraint violations and is further supported by a Kalman filter for robust state estimation and prediction. In contrast, the RL controller leverages the model-based DreamerV3 algorithm to learn control policies autonomously, adapting to different road conditions without relying on external information. The results
Uhl, Ramón Tamino, Schüle, Isabel, Ludmann, Laurin, Geist, A. René
Early Detection of the Loss of Control of Motorsport Vehicles10-09-03-002906/30/2025
The article investigates how to detect as quickly as possible whether the driver will lose control of a vehicle, after a disturbance has occurred. Typical disturbances refer to wind gusts, obstacle avoidance, a sudden steer, traversing a pothole, a kick by another vehicle, and so on. The driver may be either human or non-human. Focus will be devoted to human drivers, but the extension to automated or autonomous cars is straightforward. Since the dynamic behavior of vehicle and driver is described by a saddle-type limit cycle, a proper theory is developed to use the limit cycle as a reference trajectory to forecast the loss of control. The Floquet theory has been used to compute a scalar index to forecast stable or unstable motion. The scalar index, named degree of stability (DoS), is computed very early, in the best case, in a few milliseconds after the disturbance has ended. Investigations have been performed at a dynamic driving simulator. A 14 DoF vehicle model, virtually driven by
Della Rossa, Fabio, Fontana, Matteo, Giacintucci, Samuele, Gobbi, Massimiliano, Mastinu, Giampiero, Previati, Giorgio
Heavy-Duty Electrical Connector Performance StandardJ2030_202506 (Current)06/30/2025
This SAE Standard encompasses connectors between two cables or between a cable and an electrical component and focuses on the connectors external to the electrical component. This document provides environmental test requirements and acceptance criteria for the application of connectors for direct current electrical systems of 60 V or less in the majority of heavy-duty applications typically used in off-highway machinery. Severe applications can require higher test levels or field-testing on the intended application.
CTTC C2, Electrical Components and Systems
Developing Military Light Utility Vehicle Performance Based on Air Semi-Active Suspension System Using Recurrent Neural Network–Based Controller10-09-04-003006/19/2025
This research presents a semi-active suspension system that combines an air spring and a magneto-rheological (MR) fluid damper to produce both active force and variable damping rates based on the road conditions. The suspension system used for the military light utility vehicle (MLUV) has seven degrees of freedom. A nonlinear model predictive control system generates the desired active force for the air spring control signal, while the linear quadratic regulator (LQR) estimates the target tracking of the intended damping force. The recurrent neural network is designed to develop a controller for an identification system. To achieve the optimal voltage for the MR damper without log time, it is used to simultaneously determine the active control force of the air spring by modifying the necessary damping force tracking. The MLUV suspension system is integrated with the traction control system to improve overall vehicle stability. A fuzzy traction controller adjusts the throttle angle
Shehata Gad, Ahmed
Landing Gear StabilityAIR4894A (Current)06/17/2025
This SAE Aerospace Information Report (AIR) discusses the nature of landing gear stability, describes many common landing gear stability problems, and suggests approaches and methods for solving or avoiding them.
A-5 Aerospace Landing Gear Systems Committee
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